The present invention relates to a keyboard for choice of symbols. Such keyboards are characterized in that they have a great number of keys in the order of amount of 50, which are used frequently by the operator and are included in long series and which consequently shall be easily attainable and easily identifiable for bringing about a quick work, preferably without the aid of the eyes. With relation to these characteristics such a keyboard differs from operating keyboards which can have a very small number of keys or other operating numbers or alternatively a very large number which then are served at a low frequency and usually in short series. A middle position is represented by a keyboard on calculating machines at which the keys may be operated frequently and in long series but where they are limited to the ten figures and a few operating keys having less frequent use. This type of keyboard is also used for some other operation for example at telephones. The invention relates accordingly to the first type of keyboard which always is intended to be served by both hands.
The most frequent embodiment of the keyboard in question is the one that exists on typing machines, data terminals and the like. It is sometimes called the QWERTY-keyboard due to the arrangement of the uppermost row of letter keys. The contact surfaces of the keys are substantially in a common plane which is horizontal or slopes somewhat upwardly by its edge which is turned away from the operator. A trained typist has fingers close enough floating above the keyboard and pushes down the different keys by finger movements and small movements of the hands. This means that the hand does not have any accentuated orienting points and the touch of the fingers is more oriented by an inherent feeling of where on the plane the key in question is located than by a feeling of the relation between any stationary reference point and the key in question which is to be pushed down. A trained machine operator therefore performs a work which can be compared with piano playing and which requires a long time education and continuous training.
To reach the most frequently used keys, noting that letters occur with different frequency in the language, with the finger in question and operate them by the most movable fingers firstly the forefinger, the letters are not arranged in alphabetical order but for the most quick writing of a trained operator. This results in that the letters are difficult to find for somebody which is completely untrained. Without a well performed education one will reach a rational way of writing which besides said "floating serving" and complete knowledge of the location of the keys for the different symbols also requires such a great feeling for the exact position of the keys in the plane so that some control of the keyboard with the eyes when writing is not necessary. Only by reaching this stage one can work rationally from the manuscript or in connection with the service of a data terminal where one has a possibility to control the symbols as they are disclosed on the display unit.
The usual type of keyboard, which originally is based on relatively restricted mechanical conditions of the earlier mechanical typewriters, gives certainly a quick way of writing for a trained machine operator but they are slow and difficult to operate for the untrained and also for the one who has a long training but not a proper education. This one will be limited to so called forefinger writing having the whole time visual control of the keys. This has through the rise of the data techniques become a still greater handicap as one now needs to use the eyes for control of what is shown on the screen which is not necessary at a usual typewriter. It is also so that the distribution of the data machines has made still more groups of people using keyboards. Many of the persons who are in this new groups which often have high salaries have practically no typewriter education and will accordingly work irrationally with the traditional keyboard.
A further disadvantage with the modern technique is that one needs to use the eyes to read the keys. At electrical typewriters and data equipment one can often in a simple way by means of the electronics change the different designation of the keys with relation to the symbols; one can for example change between roman letters and greek and other symbols for example formula writings. If every single key is marked with a symbol this will make the writing more difficult. If one on the contrary does not have to read on the keys, the marking of the position of the different symbols can be shown on a scheme on the display unit. If such indirect display, and some type of display is necessary if one has to shift between different keyboards arrangements, an especially good possibility for orientation of the fingers with relation to the keys without the help of the eyes is required.
Also for the one who has a complete education in typewriting the traditional keyboard has some disadvantages. These relate especially to the fact that they require an inconvenient working position for the human physiology having the hands turned to a stressed position both in relation to the horizontal plane and to the sagittal plane (the plane through the symmetry plane of the body through the back bone and extending from the back to the former side of the breast). This stressed position gives, according to what the experience shows in many cases, rise to overstrain of some muscles and muscular attachments having damage as a result.
These disadvantages are known. To make a physiologically more correct handposition possible it has been proposed to divide the keys in two or more groups, which have an angel relative to each other. This has for example been proposed in DE 2 607 126 and U.S. Pat. No. 4,483,634. The U.S. Pat. Nos. 3,990,565 and 4,661,005 do also propose dividing of the usual keyboard on two separate parts on separate elements which can be positioned in different angular positions. Through these solutions one has obtained an ergonomically better solution but said orienting problem for the one who is less trained has not been solved. An example of an attempt to solve said orienting problem is disclosed in DE 1 810 119 in which publication an operating arrangement is shown where all fingers have practically locked positions and where each finger serves only two keys. This type of solution is however not suitable for typewriters where a demand has to be put on the possibility to write quickly as well as a good orientation. The present invention relates besides that as mentioned above, not to the last mentioned type of equipment having a few keys.
The disadvantages and problems described connected with the keyboards for choice of symbols are solved by the present invention where the keys for the most frequently used symbols are divided in two groups having mutually the same number and with contact surfaces for the keys in each group arranged in each of its own reference surface having reference surfaces in a position for placing the fingers except for the thumb for the left hand on one reference surface and for the right hand on the others reference surface. The reference surfaces are arranged at opposite sides of said sagittal plane of an operator in such a way that the reference surfaces slope towards the horizontal plane that is transversely to the sagittal plane having its edges upwardly turned in against each other and forming an angle with the horizontal plane for each plane of 10.degree.-50.degree. preferably about 30.degree. and angularly to each other having their edges turned away from the operator each forming an angle to the sagittal plane of 10.degree.-45.degree. preferably about 30.degree.. The keys in each group are divided in a number of substantial vertically rows having four keys in each row. At the upper side of said reference plane there are longitudinal supports for the thumb area of each hand, along which support the thumb can slide, the keys and the thumb supports being mutually so arranged that by support with the thumb in a displaced position of the hand a position for said fingers is obtained each opposite one of the four keys in the first row and a second displacement position opposite the keys in a second row etc with relation to all keys for the highly frequently used symbols. Herethrough all keys for these symbols will be touchable by placing the hand in a determined displacement position and pushing a key with the finger located opposite the key in this displacement position.
Through the present invention a keyboard has been obtained that, with regard to the functions of the human bodies which gives us a possibility to tactilly recognize objects that quickly gives the one who uses it, a possibility to orient himself to find the keys in question which are to be operated.
Further a keyboard has been obtained which does not bind the movements of the fingers and the hand in such way that a quick writing of for example running text is obstructed.
Still a further advantage is that the keyboard has been constructed taken into regard the human physiology so that unnecessary and unsuitable stress of the body can be avoided resulting in minimizing the risk for a muscle overstraining and damage.